hm-nodejs-testing

Use Fastify's built-in app.inject() method to send HTTP requests directly to the app instance without binding a port. Call await app.ready() before injecting and await app.close() in teardown to release connections.

Vitest is recommended because it uses Vite's native TypeScript and ESM support, making it significantly faster than Jest with ts-jest. It offers a Jest-compatible API, so test syntax like describe, it, and vi.fn() works the same.

No, integration tests should use a real test database with Prisma migrations applied via prisma migrate deploy. Mocking Prisma defeats the purpose of integration tests, which exist to catch database constraints, serialization, and hook ordering issues.

Mock the queue module at the service boundary using vi.mock() and stub the add method to return a fake job id. This prevents tests from dispatching real jobs to Redis while still verifying the service attempted to enqueue work.

Tests share state when they use the same Redis DB index as development. Configure a separate index in .env.test, such as redis://localhost:6379/1, and flush it in a beforeEach cleanup hook.

The Testing Trophy prioritizes static analysis, then mostly integration tests hitting real APIs and databases, supported by unit tests for pure logic, with few E2E tests. It favors integration over unit tests because they catch more real defects.